Intercom systems have been employed to help facilitate communication throughout premises such as a home or office. Using an intercom, one can talk or listen among multiple locations. Current intercom systems can be divided into two categories—wireless and wired. Each possesses serious disadvantages.
Wireless intercom systems rely on simple wireless broadcast technology to broadcast a signal from one handset to all other handsets. Some models permit a user to select which channel to broadcast on, but an associated receiver needs to be set to the same channel in order to receive the broadcasted message. These simple wireless devices suffer from poor quality (due to radio wave interference from other devices and weak signals) and have no privacy or security; anyone can listen in on transmissions by monitoring the channel.
Wired intercom systems are hard-wired together, either via telephone lines or Ethernet cables. These systems are mounted in place in the wall, and communicate with each other through their wired analog or digital connections. These systems provide greater reliability and privacy than wireless intercoms because of their wired connection, but quality is often poor because of interference from power lines. In addition, many wired intercom systems employ a “master/slave” model in which communication is permitted between master and slave devices but two slave devices cannot communicate with each other. Finally, these systems are costly due to the requirement to wire them together.